借鉴：https://blog.csdn.net/wangjicong_215/article/details/79744599
window 通过adb shell dumpsys activity | findstr “mFocus”
Linux 通过adb shell dumpsys activity | grep “mFocus”
window 通过adb shell dumpsys activity | findstr “mResume”
Linux 通过adb shell dumpsys activity | grep “mResume”
原文：https://www.cnblogs.com/cheneyboon/p/11729326.html